Iodine-131 therapy alters the immune/inflammatory responses in the thyroids of patients with Graves' disease

Abstract

The aim of the present study was to evaluate the serum levels of interleukin-6 (IL-6), CXC chemokine ligand-10 (CXCL-10) and intercellular adhesion molecule-l (ICAM-1) in patients with Graves' disease (GD) following iodine-131 (¹³¹I) therapy. A total of 30 patients with GD participated in the present study. Serum cytokine levels were measured with ELISA, and correlation analyses were performed. Serum levels of IL-6, CXCL-10 and ICAM-1 were significantly higher in patients with GD prior to treatment than those in the control subjects (P<0.01). Following ¹³¹I therapy, the serum levels of IL-6 and CXCL-10 in patients with GD were markedly increased within the first week, gradually decreased to the pretreatment level in the subsequent six months and decreased further at 18 months post-treatment. However, the serum levels of IL-6 and CXCL-10 in patients with GD at 18 months following ¹³¹I therapy remained significantly higher than in control subjects (P<0.01). Conversely, serum ICAM-1 levels in patients with GD were gradually increased in the 12 months following ¹³¹I therapy and reached a relatively stable level thereafter. Furthermore, the Pearson's correlation analysis indicated that the serum levels of IL-6, CXCL-10 and ICAM-1 were not associated with free triiodothyronine, the free thyroxine index, and thyroid-stimulating hormone in these patients. ¹³¹I therapy was able to alter the immune/inflammatory responses in the thyroids of patients with GD. However, these cytokines (IL-6, CXCL-10, and ICAM-1) are not associated with thyroid function; therefore, they cannot be used as prognostic markers for the ¹³¹I therapy of GD.

Keywords: CXC chemokine ligand-10; Graves' disease; intercellular adhesion molecule-l; iodine-131 therapy; leukin-6.

Figure 1.

Serum levels of IL-6 in patients with GD before and after ¹³¹I therapy. Serum levels of IL-6 in patients with GD were determined using ELISA, prior to ¹³¹I therapy, at 1 w, and 1, 2, 3, 6, 12 and 18 m post-treatment. **P<0.01 vs. the corresponding control group; ^#P<0.05 vs. the before-treatment level in patients with GD. IL, interleukin; GD, Graves' disease; ¹³¹I, iodine-131; w, week; m, month.

Figure 2.

Serum levels of CXCL-10 in patients with GD before and after ¹³¹I therapy. Serum levels of CXCL-10 in patients with GD were determined using ELISA, prior to ¹³¹I therapy, at 1 w, and 1, 2, 3, 6, 12 and 18 m post-treatment. **P<0.01 vs. the corresponding control group; ^#P<0.05 vs. the before-treatment level in patients with GD. CXCL, CXC chemokine ligand; GD, Graves' disease; ¹³¹I, iodine-131; w, week; m, month.

Figure 3.

Serum levels of ICAM-1 in patients with GD before and after ¹³¹I therapy. Serum levels of ICAM-1 in patients with GD were determined using ELISA, prior to ¹³¹I therapy, at 1 w, and 1, 2, 3, 6, 12 and 18 m post-treatment. **P<0.01 vs. the corresponding control group; ^#P<0.05 vs. the before-treatment level in patients with GD. ICAM, intracellular adhesion molecule; GD, Graves' disease; ¹³¹I, iodine-131; w, week; m, month.